You will probably find one of the reasons for the N0.5 Bayonet being in short supply is this.
The BritishGovernment has Moved forward it's Policy of Not selling Weapons Etc Onto the Civillian Market.
Yes to Forigen M.O.D Departmets, subject to the Correct Paperwork. End user Cert's Etc.
I have Handled MANY Hundereds & Hundereds of Deactivated Sterling Mk IV S.M.Gs On the Civillian Circuit. As well as sold a LOT of them Myself.
They are ALWAYS a Sterling Comercial Weapon IE: A MK IV, & NOT a British L2A3.
Easyist thing to spot is Firstly, The BRITSH Service variant Had a Mod done to strengthen the Butt at the Circular 'U' / Yoke bend near the Middle.
Secondly: The Mag Housing will Be Marked with a UE/ UF/ Etc PREFIX to the serial Number.
The STERLING COMMERCIAL will be USUALLY Marked with a KR series PREFIX to the Number & the Butt Will NOT Have the Mod Plate welded in the Above mentioned Place.
The Brit Policy is to Guillotine or Gas Axe all Smallarms Not sold out of the Country. Or the same if not sold to a Dealer Here in the UK to be subsequently Exported OUT of here.
I know of a Dealer who is a Good Friend of Mine who knows of LOADS os SLR's sold to Germany. ALL EX Brit M.O.D. They will NOT sell to him for Re-importation to the UK.
Because, there was a Proviso in the sale deal. They can buy them, but they must NOT be re-imported. If they do this, they will NEVER be allowed to buy anything from the M.O.D again!
All that being said, I have taken possesion of a GENUINE Deactivated Fazakerly Manufactured L2A3 & is UF serial Number marked!
It must have 'Got out' early in it's life, because it did NOT have the Butt Mod done to it!
(It certainly DOES now!)
It is the ONLY One I have seen in Private hands.
So, If they Cut up all the Obsolete Sterlings (Some MAY have been refurbed & gone into War Reserve) Then it stands to reason that the Bayonets as 'Weapons' MAY have also been destroyed as well.
Museums will have been offered some as the 'Norm' over here before destruction (Peter can confirm this)
The ONLY thing in quantity that HAS been released, is the webbing slings!
Even the cleaning kits are NOT about in the quantities that they should be if officially released. (Unlike the SLR Kits!)
This MAY go some way to explain the shortage in Collectors terms. Of WHY the No.5 Bayonet is not seen commonly on the Militaria Circuit.
Unlike the SLR Bayonets, Magazines, slings, Cleaning kits Etc. Which WERE Officially released onto the Civillian Market to Appropriate Licensed Dealers.